MTAdmob is probably the easiest and best plugin to add Google Admob to your Xamarin Android and iOS apps.
You can add Banners, Interstitials and Rewarded Videos to your app with a single line of code.
And now MTAdmob is Open Source so if you want to know how it works or if you want to contribute to it, you can go on
and have a look or maybe send a pull request with some new features.
Again if you need a tutorial, you can have a look at
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